1952 Chevy 1/2 ton rear glass

[wildfifty2]

I am replacing the rear cab glass in my 52 Chevy 1/2 ton truck. I have removed the old glass and done the needed clean up and painting.. I am having a tough time keeping the rubber gasket on the new glass while getting ready for the install. The rubber stays on nicely until I round the corners and then it twists and slided off the glass. I have had some luck using masking tape to hold the rubber at the corners but have yet to make the complete distance around the glass. Does anyone have any tips to help with this project? I feel confident that once i get past this point... I will go well from there Thanks in advance for you input...